Deutsche Bank Suspends Traders, Regulators Visit Citigroup

The heat intensified Wednesday on the two most-powerful banks in foreign exchange, as it emerged that U.S. regulatory officials were on a "fact-finding" tour of Citigroup Inc.'s London office and that Deutsche Bank AG had suspended several employees as part of a sprawling investigation into practices by currency traders.

The officials from the New York Federal Reserve and the Office of the Comptroller of the Currency have...